Theoretical Study Of Fuel Tank Flammability Assessment Technology Based On Physicochemical Characteristics Of Domestic Fuels

The combustion and explosion of aircraft fuel tank are the one of the major problems of thecurrent threats to the aviation safety. Therefore, the design of the fire explosion suppression device ormethod in the aircraft fuel system and the assessment of the aircraft fuel tank flammability assessmentare required definitely. However, due to the lack of essential physicochemical properties of thedomestic fuels research, there are many defects to design the domestic aircraft fuel tank inertingsystem and assess the flammability of the domestic aircraft fuel tanks assessment. So, the relevantstudies are necessary and should be carried out in this paper.Due to the lack of the basic properties for the domestic fuel and flammable limits, the domesticRP-3-type fuel performance characteristics are systematically summarized by the pattern ofphysical-chemical, thermal physical-chemical properties and combustible factors on the basis ofdomestic and foreign literature; deep studies of domestic RP-3the fuel flammable and combustiblelimit based on the performance characteristics of RP-3are presented, including not only thecalculation of the RP-3fuel flammability limit, but also a detailed analysis of the influence oftemperature, pressure, oxygen concentration, the concentration of inert gas and other factors on theflammable limits, and a RP-3fuel combustible limit diagram is obtained. The research results in that:(1) temperature and pressure have a minimal impact on the fuel RP-3lower flammable limit whiledoing a significant effect on its upper flammable limit;(2) saturation vapor pressure has no effecteither on the lower limit of the RP-3fuel or the upper limit of the RP-3, but it affects the flammablelimits to some extent;(3) ignition energy and the oxygen concentration in the upper flammable limitof the RP-3fuel have a larger impact than the lower flammable limit;(4) the concentration of nitrogenhas a greater impact on flammable limits of RP-3.Besides, the minimum oxygen concentration and theminimum concentration of nitrogen required by fuel tank inerting can be determined by theflammable limit diagram of RP-3fuel.Based on the research of the basic domestic fuel properties, a real aircraft fuel tank flammabilityassessment technique is studied in this paper. Adopting the aircraft fuel tank flammability assessmentmethod developed by FAA, the main factors affecting the flammability assessment are firstlyevaluated in this paper. Secondly, these factors in the pattern of orthogonal experimental method areanalyzed and compared in the paper; thirdly, the impact of fuel properties on the assessment results isalso analyzed and calculated; Finally, aiming at the real tank structure and layout of a domesticregional jet, the fuel tank flammability assessment work is carried out in this paper, then the properimprovement measure based on the results of the assessment is submitted.The study presented in this paper not only makes a major scientific significance of filling thegaps in domestic research, but also meets an urgent need for the application of domestic aircraftdevelopment; the research has played a positive role in promoting the development of civil aircraftand military aircraft.